void OSSemPend (OS_EVENT *pevent, INT16U timeout, INT8U *perr)
{
INT8U pend_stat;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0
if (perr == (INT8U *)0) { /* Validate 'perr' */
return;
}
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*perr = OS_ERR_PEVENT_NULL;
return;
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_SEM) { /* Validate event block type */
*perr = OS_ERR_EVENT_TYPE;
return;
}
if (OSIntNesting > 0) { /* See if called from ISR ... */
*perr = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return;
}
if (OSLockNesting > 0) { /* See if called with scheduler locked ... */
*perr = OS_ERR_PEND_LOCKED; /* ... can't PEND when locked */
return;
}
OS_ENTER_CRITICAL();
if (pevent->OSEventCnt > 0) { /* If sem. is positive, resource available ... */
pevent->OSEventCnt--; /* ... decrement semaphore only if positive. */
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return;
}
/* Otherwise, must wait until event occurs */
OSTCBCur->OSTCBStat |= OS_STAT_SEM; /* Resource not available, pend on semaphore */
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK;
OSTCBCur->OSTCBDly = timeout; /* Store pend timeout in TCB */
OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
OS_EXIT_CRITICAL();
OS_Sched(); /* Find next highest priority task ready */
OS_ENTER_CRITICAL();
if (OSTCBCur->OSTCBStatPend != OS_STAT_PEND_OK) { /* See if we timed-out or aborted */
pend_stat = OSTCBCur->OSTCBStatPend;
OS_EventTOAbort(pevent);
OS_EXIT_CRITICAL();
switch (pend_stat) {
case OS_STAT_PEND_TO:
default:
*perr = OS_ERR_TIMEOUT; /* Indicate that didn't get event within TO */
break;
case OS_STAT_PEND_ABORT:
*perr = OS_ERR_PEND_ABORT; /* Indicate that we aborted */
break;
}
return;
}
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
}
void *OSMboxPend (OS_EVENT *pevent, INT16U timeout, INT8U *perr)
{
void *pmsg;
INT8U pend_stat;
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr = 0;
#endif
#if OS_ARG_CHK_EN > 0
if (perr == (INT8U *)0) { /* Validate 'perr' */
return ((void *)0);
}
if (pevent == (OS_EVENT *)0) { /* Validate 'pevent' */
*perr = OS_ERR_PEVENT_NULL;
return ((void *)0);
}
#endif
if (pevent->OSEventType != OS_EVENT_TYPE_MBOX) { /* Validate event block type */
*perr = OS_ERR_EVENT_TYPE;
return ((void *)0);
}
if (OSIntNesting > 0) { /* See if called from ISR ... */
*perr = OS_ERR_PEND_ISR; /* ... can't PEND from an ISR */
return ((void *)0);
}
if (OSLockNesting > 0) { /* See if called with scheduler locked ... */
*perr = OS_ERR_PEND_LOCKED; /* ... can't PEND when locked */
return ((void *)0);
}
OS_ENTER_CRITICAL();
pmsg = pevent->OSEventPtr;
if (pmsg != (void *)0) { /* See if there is already a message */
pevent->OSEventPtr = (void *)0; /* Clear the mailbox */
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (pmsg); /* Return the message received (or NULL) */
}
OSTCBCur->OSTCBStat |= OS_STAT_MBOX; /* Message not available, task will pend */
OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK;
OSTCBCur->OSTCBDly = timeout; /* Load timeout in TCB */
OS_EventTaskWait(pevent); /* Suspend task until event or timeout occurs */
OS_EXIT_CRITICAL();
OS_Sched(); /* Find next highest priority task ready to run */
OS_ENTER_CRITICAL();
if (OSTCBCur->OSTCBStatPend != OS_STAT_PEND_OK) { /* See if we weren't given the message */
pend_stat = OSTCBCur->OSTCBStatPend;
OS_EventTOAbort(pevent); /* Timed out, Make task ready */
OS_EXIT_CRITICAL();
switch (pend_stat) {
case OS_STAT_PEND_TO:
default:
*perr = OS_ERR_TIMEOUT; /* Indicate that a timeout occured */
break;
case OS_STAT_PEND_ABORT:
*perr = OS_ERR_PEND_ABORT; /* Indicate that we aborted */
break;
}
return ((void *)0); /* Return a NULL message */
}
pmsg = OSTCBCur->OSTCBMsg;
OSTCBCur->OSTCBMsg = (void *)0; /* Yes, clear message received */
OSTCBCur->OSTCBStat = OS_STAT_RDY;
OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0; /* No longer waiting for event */
OS_EXIT_CRITICAL();
*perr = OS_ERR_NONE;
return (pmsg); /* Return the message received */
}